[INFO] cloning repository https://github.com/pfeilbr/rust-playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/pfeilbr/rust-playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpfeilbr%2Frust-playground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpfeilbr%2Frust-playground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] acc20eccef22b80c673abb95eb71875bae0f9152
[INFO] checking pfeilbr/rust-playground against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpfeilbr%2Frust-playground" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/pfeilbr/rust-playground
[INFO] finished tweaking git repo https://github.com/pfeilbr/rust-playground
[INFO] tweaked toml for git repo https://github.com/pfeilbr/rust-playground written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/pfeilbr/rust-playground on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/pfeilbr/rust-playground already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 19e09d48b76a41b51cad7a1b961b4d3bf66c66d234b19e8a61d6a1a726ce82af
[INFO] running `Command { std: "docker" "start" "-a" "19e09d48b76a41b51cad7a1b961b4d3bf66c66d234b19e8a61d6a1a726ce82af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "19e09d48b76a41b51cad7a1b961b4d3bf66c66d234b19e8a61d6a1a726ce82af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "19e09d48b76a41b51cad7a1b961b4d3bf66c66d234b19e8a61d6a1a726ce82af", kill_on_drop: false }`
[INFO] [stdout] 19e09d48b76a41b51cad7a1b961b4d3bf66c66d234b19e8a61d6a1a726ce82af
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid -Dunmustuse_in_always_ok" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9fa1310dcef3036d959fec2a2e381dbdb6f4038e9b4c2f018dc409b16f99ce97
[INFO] running `Command { std: "docker" "start" "-a" "9fa1310dcef3036d959fec2a2e381dbdb6f4038e9b4c2f018dc409b16f99ce97", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.66
[INFO] [stderr]    Compiling unicode-ident v1.0.11
[INFO] [stderr]    Compiling serde v1.0.188
[INFO] [stderr]    Compiling serde_json v1.0.73
[INFO] [stderr]     Checking memchr v2.6.3
[INFO] [stderr]     Checking unsafe-libyaml v0.2.9
[INFO] [stderr]    Compiling num-traits v0.2.16
[INFO] [stderr]     Checking indexmap v2.0.0
[INFO] [stderr]     Checking time v0.1.45
[INFO] [stderr]     Checking csv-core v0.1.10
[INFO] [stderr]    Compiling quote v1.0.33
[INFO] [stderr]    Compiling syn v2.0.31
[INFO] [stderr]    Compiling serde_derive v1.0.188
[INFO] [stderr]     Checking serde_yaml v0.9.25
[INFO] [stderr]     Checking chrono v0.4.29
[INFO] [stderr]     Checking csv v1.2.2
[INFO] [stderr]     Checking rust-playground v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error: this type will no longer be must used: Result<std::string::String, Infallible>
[INFO] [stdout]   --> src/main.rs:86:13
[INFO] [stdout]    |
[INFO] [stdout] 86 |     let s = String::from_str("foo").unwrap();
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust-playground` (bin "rust-playground" test) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "9fa1310dcef3036d959fec2a2e381dbdb6f4038e9b4c2f018dc409b16f99ce97", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9fa1310dcef3036d959fec2a2e381dbdb6f4038e9b4c2f018dc409b16f99ce97", kill_on_drop: false }`
[INFO] [stdout] 9fa1310dcef3036d959fec2a2e381dbdb6f4038e9b4c2f018dc409b16f99ce97